Disables the FIX-ENVIRON bandaid.
Seems not to be necessary anymore... for now.
Adds EMMS-SORT-MODIFIED to emms-channel.

It could be more general to suffice for EMMS' deficiency,
but this is a patch in lieu of a full replacement.
W3M-SAVE-DELETED-BUFFERS uses PUSHNEW.
Just PUSH'ing led to too many repeated URLs in practice.
DELETED-BUFFERS is renamed to W3M-DELETED-BUFFERS
Because this is Emacs; the namespace is global, so we need to be unambiguous.